Quantitative proteomic analysis of differentially expressed proteins in the toxicity-lost mutant of Alexandrium catenella (Dinophyceae) in the exponential phase

► Alexandrium catenella is a toxic dinoflagellate which can produce paralytic shellfish toxin. ► The molecular mechanisms regulating toxin biosynthesis remain unclear. ► DIGE reveals 67 differentially expressed proteins in the toxicity-lost mutant A. catenella. ► Changes in certain biological processes might block toxin production in the mutant A. catenella. ► Toxin biosynthesis is a complex and comprehensive process in toxic A. catenella.